Examine source code of YouTube Custom Looper

{
  "manifest_version": 2,
  "name": "YouTube Custom Looper",
  "version": "1.2",
  "description": "Loop the favourite parts of your YouTube videos!",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "options_ui": {
    "page": "settings.html"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/pepe-rotate-48.gif",
      "128": "icons/pepe-rotate.gif"
    }
  },
  "icons": {
    "48": "icons/pepe-rotate-48.gif",
    "128": "icons/pepe-rotate.gif"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1e0ef38e-0496-4a23-b463-e591c43a4d41}"
    }
  }
}